Article 21U.K.Refusal or suspension of enforcement
1.The grounds of refusal or suspension of enforcement under the law of the Member State of enforcement shall apply in so far as they are not incompatible with the application of paragraphs 2 and 3.
2.The competent authority in the Member State of enforcement shall, on application by the debtor, refuse, either wholly or in part, the enforcement of the decision of the court of origin if the right to enforce the decision of the court of origin is extinguished by the effect of prescription or the limitation of action, either under the law of the Member State of origin or under the law of the Member State of enforcement, whichever provides for the longer limitation period.
Furthermore, the competent authority in the Member State of enforcement may, on application by the debtor, refuse, either wholly or in part, the enforcement of the decision of the court of origin if it is irreconcilable with a decision given in the Member State of enforcement or with a decision given in another Member State or in a third State which fulfils the conditions necessary for its recognition in the Member State of enforcement.
A decision which has the effect of modifying an earlier decision on maintenance on the basis of changed circumstances shall not be considered an irreconcilable decision within the meaning of the second subparagraph.
3.The competent authority in the Member State of enforcement may, on application by the debtor, suspend, either wholly or in part, the enforcement of the decision of the court of origin if the competent court of the Member State of origin has been seised of an application for a review of the decision of the court of origin pursuant to Article 19.
Furthermore, the competent authority of the Member State of enforcement shall, on application by the debtor, suspend the enforcement of the decision of the court of origin where the enforceability of that decision is suspended in the Member State of origin.